"Under maintenance..." since more than 24 hours?

[heinnapp]

I try to post a reply in the forum but keep on getting this error message since more than 24 hours:
"The site is under maintenance which will be finished during the next hour."
How can this issue be fixed?

[YanPowerful]

Maybe you using banwords or third party emojis.
I tried using third party emojis and got the same notification.